Setup > SMS Gateway list
From Shopnix Help
How to get SMS gateways list added in your shop?
SMS will be sent to customers when an order is placed and when the order is moved to shipping. To use the SMS feature, you'll need to purchase an SMS package from any of the gateways like SMS Gupshup or SMS infini.
For getting the list of SMS Gateways added in your shop you need to follow-
Go to Admin > Setup > SMS Gateway
Now you will get the list of SMS Gateways which are added in your shop as shown in below image-
If you have more queries or would like assistance with this please contact us on firstname.lastname@example.org.